Facilitating Antibiotic Stewardship with Procalcitonin

Amesh A. Adalja, MD, FACP, FACEP, FIDSA, June 24, 2016

One of the major drivers of antibiotic overuse is the lack of confidence many prescribers have in discontinuing antibiotics that have been prescribed empirically. Nowhere is this decision more crucial than in the intensive care unit, where critically ill patients often on the precipice of death are cared for. However, in recent years, as antibiotic stewardship has become increasingly emphasized, novel biomarkers hold the promise to optimize antibiotic prescribing and potentially facilitate the safe discontinuation of antibiotics. A new study, published in Lancet Infectious Diseases, reports on the results of a trial in which the biomarker procalcitonin—a molecule specific for bacterial infection—was employed to guide antibiotic discontinuation.

Prospective, Multicenter, Randomized Trial

The trial, known as SAPS, was conducted in the Netherlands at 12 centers and included nonimmunosuppressed adult patients admitted to the ICU for presumed or proven infection who received antibiotic therapy. The patients, over 80% of whom had sepsis or severe sepsis, were randomized to a study group or usual care group. The study population had daily procalcitonin measurements, and the protocol called for cessation of antibiotics when procalcitonin levels fell by 80% or reached a threshold level of less than 0.5 micrograms per milliliter of blood. The primary outcome was antibiotic use as well as mortality. Study enrollment included 1,546 patients in the modified intention-to-treat population.

Procalcitonin Use Yields Promising Results

In terms of antibiotic usage, those patients in the procalcitonin-guided group experienced a statistically lower exposure to antibiotics by 1.8 days as well as a lower duration of antibiotic use. Antibiotic-free days were also more common in the study group when compared to those in the usual care group.

Mortality, a major component of how palatable a procalcitonin-guided approach will be to clinicians, was decreased in those guided by procalcitonin at both 28 days and 1 year, establishing the safety of the practice.

Tools to Facilitate Stewardship

This study is of high importance as it provides compelling evidence that, in a critically ill patient cohort, de-escalating antibiotics by using the biomarker procalcitonin is not only safe but improves outcomes. As antibiotic stewardship rises as a priority in healthcare settings, using biomarker-based strategies will increasingly become the norm. Such a scenario, coupled with evidence like that provided by the SAPS trial, argues for more widespread adoption of procalcitonin and a host of other tests (eg, molecular diagnostic viral panels).